WO2003091085A1

WO2003091085A1 - Method and device for controlling maneuverability of vehicle

Info

Publication number: WO2003091085A1
Application number: PCT/JP2003/005073
Authority: WO
Inventors: Hiroaki Kato; Minekazu Momiyama; Yoshiyuki Yasui; Wataru Tanaka; Kenji Asano; Yuzou Imoto; Eiichi Ono; Yuji Muragishi
Original assignee: Toyoda Koki Kabushiki Kaisha
Priority date: 2002-04-26
Filing date: 2003-04-21
Publication date: 2003-11-06
Also published as: DE60316940D1; EP1508501A4; DE60316940T2; JP2003320948A; JP4092389B2; US20050167181A1; EP1508501B1; US7055645B2; EP1508501A1

Abstract

A method and a device for controlling the maneuverability of a vehicle, the method comprising the steps of obtaining, by a vehicle maneuverability controlling device, the steer angle θh of a steering wheel based on the rotating angle θpm of an assist motor (24m) detected by a rotating angle sensor (24s) and the rotating angle θvm of a gear ratio variable motor (32m) detected by a rotating angle sensor (32s) and performing the VGRS control processing (40a) of a gear ratio variable mechanism based on the obtained steer angle θh, whereby since the steer angle θh of the steering wheel is obtained based on the rotating angle θvm used for the VGRS control processing (40a) of the gear ratio variable mechanism and the rotating angle θpm used for the ESP control processing (30a) of an EPS actuator, the steer angle θh of the steering wheel can be obtained even if a steer angle sensor is absent, and thus the number of parts of the vehicle maneuverability control device can be reduced.

Description

-1-Description Vehicle motion control method and vehicle motion control device

Technical field

The present invention relates to a vehicle motion control method and a vehicle motion control device. Background art

As a vehicle motion control device equipped with a variable transmission ratio mechanism that varies the transmission ratio by driving a variable gear ratio motor in the middle of the steering transmission system that connects the steering wheel (handle) and the steered wheels, see FIG. As shown in Fig. 5, steering wheel (handle) 21, first steering shaft 22, second steering shaft 23, EPS actuator 24, rod 25, steering angle sensor 26, vehicle speed sensor 2 7, a vehicle motion control device 100 including a torque sensor 28, an EPS-ECU 30, a variable gear ratio mechanism 32, a VGRS-ECU 40, and the like. Such a “transmission ratio variable mechanism that varies the transmission ratio by driving an electric motor in the middle of a steering transmission system that connects the steering wheel 21 and the steered wheels” is referred to as V GRS

(Vriable Gear Ratio System).

That is, one end of the first steering shaft 22 is connected to the steering wheel 21, and the input side of the variable gear ratio mechanism 32 is connected to the other end of the first steering shaft 22. The variable gear ratio mechanism 32 includes a variable gear ratio motor 32 m, a reduction gear 32 g, and the like. One end of the second steering shaft 23 is connected to this output side, and the second steering shaft The other end of the shaft 23 is connected to the input side of the EPS actuator 24. The EPS actuator 24 is an electric power steering device. The EPS actuator 24 can convert the rotational motion inputted by the second steering shaft 23 into the axial motion of the rod 25 by a rack / pinion gear (not shown) and output the same. At the same time, an assist motor according to the steering state is generated by an assist motor 24 m controlled by the EPS-ECU 30 to assist the driver in steering. The rotation angle of the first steering shaft 22 (steering Angle) is detected by the steering angle sensor 26 to the VGRS_ECU 40 as a steering angle signal 6 h, and the steering torque by the second steering shaft 23 is detected by the torque sensor 28 to be EPS control processing as a torque signal Tp. The vehicle speed is detected by a vehicle speed sensor 27 and input as a vehicle speed signal V to EPS_ECU 30 and VGRS_ECU 40, respectively. The rod 25 is equipped with unillustrated steering wheels.

With this configuration, in the variable gear ratio mechanism 32 and the VGRS-ECU 40, the ratio of the output gear to the input gear is changed in real time according to the vehicle speed by the variable gear ratio motor 32m and the reduction gear 32g. And the ratio of the output angle of the second steering shaft 23 to the steering angle of the first steering shaft 22 is varied. In addition, the EPS actuator 24 and the EPS_ECU 30 use an assist motor 24 to assist the driver in steering according to the driver's steering state and vehicle speed detected by the torque sensor 28 and the vehicle speed sensor 27. Generated by m. This makes it possible to set the steering gear ratio corresponding to the vehicle speed, for example, so that the output angle of the variable gear ratio mechanism 32 becomes larger than the steering angle of the steering wheel 21 when the vehicle is stopped or running at low speed. While it is possible to set the output angle of the variable gear ratio mechanism 32 to be smaller than the steering angle of the wheel 21, the assist motor 24 m generates an appropriate assist force corresponding to the vehicle speed It becomes possible.

For example, when the vehicle is stopped or running at low speed, the steering gear ratio by the variable gear ratio mechanism 32 is set small and the assist power by the assist motor 24 m is increased. Steering transportation is greatly cut off. This makes it easier for the driver to steer. On the other hand, when the vehicle is traveling at high speed, the assisting force of the assist motor 24 m is reduced and the steering gear ratio is set by the variable gear ratio mechanism 32, so that the steering operation becomes heavy and Even if the steering is turned sharply, the steered wheels are only slightly cut. This can be expected to further improve the stability of vehicle control.

However, according to such a vehicle motion control device 1◦0, as shown in FIG. 5, the assist motor 24 m rotation angle sensor 24 s and the gear ratio variable motor 32 2 Many sensors are used, such as a steering angle sensor 26, a vehicle speed sensor 27, and a torque sensor 28, including a rotation angle sensor 32s of m. For this reason, the vehicle motion control device 100 has a problem in that the use of such sensors frequently causes an increase in product cost and prevents a reduction in the failure rate. On the other hand, considering the motion control performance of the vehicle, if measures such as simply replacing the sensor with a low-resolution low-cost sensor or reducing the number of sensors are used, the EPS control There is a problem that the control performance of 30a or VGRS control processing 40a is degraded, or the control itself is disabled.

The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a vehicle motion control method and a vehicle motion control device capable of reducing the number of parts. is there.

Another object of the present invention is to provide a vehicle motion control method and a vehicle motion control device that can improve the vehicle motion control performance. Disclosure of the invention

In order to achieve the above object, in the vehicle motion control method according to claim 1, the transmission ratio is varied by driving a variable gear ratio motor in a steering transmission system connecting the handle and the steered wheels. A motion control method for a vehicle, comprising: a variable transmission ratio mechanism; and an assist motor for supplementing a steering force based on a steering torque generated on an output shaft of the variable transmission ratio mechanism, comprising: a rotation angle θ of the assist motor. a first step of detecting ρπι, a second step of detecting a rotation angle 0 vm of the variable gear ratio motor, and a detection of the rotation angle 0 pm detected in the first step and the second step. Controlling the transmission ratio variable mechanism based on the steering angle of the steering wheel obtained in the third step, and a third step of obtaining a steering angle of the steering wheel based on the obtained rotation angle Θvm. And technical features to be performed.

According to the first aspect of the present invention, the steering angle of the steering wheel is obtained based on the rotation angle 検出 pm detected in the first step and the rotation angle θ νηι detected in the second step. The transmission ratio variable mechanism that varies the transmission ratio of the steering transmission system is controlled based on the steering angle. Thus, based on the rotation angle θ νπι used for controlling the gear ratio variable motor and the rotation angle 6 pm used for controlling the assist motor, Therefore, the steering angle of the steering wheel can be obtained even without a mechanical or electrical component for detecting the steering angle, such as a steering angle sensor. Therefore, since components for detecting such a steering angle can be eliminated, the number of components can be reduced.

Further, in the vehicle motion control method according to the second aspect, in the first aspect, the rotation angle 0 pm in the first step may be detected, and the rotation angle 0 in the second step may be detected. A technical feature is that a rotation angle is input to at least one of the detections of vm via a deceleration means.

According to the second aspect of the present invention, since the rotation angles are input via the deceleration means for detecting the rotation angles of 6 pm and 0 vm, the resolution of the input rotation angles of 0 pm and 0 vm is determined. Can be enhanced. As a result, in the third step described in claim 1, the steering angle of the steering wheel can be obtained based on the rotation angles 、 pm and Θ vm with high resolution, so that the resolution of the obtained steering angle is also high. Enhanced. Therefore, since the variable transmission ratio mechanism is controlled based on the steering angle of the high-resolution steering wheel, the operation control performance of the vehicle can be improved.

Further, in the vehicle motion control device according to claim 3, a transmission ratio variable mechanism that varies a transmission ratio by driving a gear ratio variable motor in a steering transmission system that connects the steering wheel and the steered wheels. An assist motor for supplementing a steering force based on a steering torque generated on an output shaft of the transmission ratio variable mechanism, wherein the first motor controller detects a rotation angle 0 pm of the assist motor. Rotation angle detection means, second rotation angle detection means for detecting a rotation angle θ νηι of the gear ratio variable motor, rotation angle 0 pm detected by the first rotation angle detection means, and the second rotation Steering angle calculating means for obtaining a steering angle of the steering wheel based on the rotation angle θ νηι detected by the angle detecting means.The steering angle calculating section calculates the steering angle of the steering wheel based on the steering angle obtained by the steering angle calculating means. Variable transmission ratio The technical feature is to control the mechanism.

According to the third aspect of the present invention, the handle is determined based on the rotation angle 0 pm detected by the first rotation angle detection means and the rotation angle θ νηι detected by the second rotation angle detection means. The steering angle is determined, and the variable transmission ratio mechanism that varies the transmission ratio of the steering transmission system is controlled based on the determined steering angle of the steering wheel. As a result, the rotation angle 0 vm used for controlling the variable gear ratio motor and the rotation angle 制御 used for controlling the assist motor Θ Since the steering angle of the steering wheel is obtained based on pm, it is possible to obtain the steering angle of the steering wheel without a mechanically or electrically detecting component such as a steering angle sensor. Therefore, since a component for detecting such a steering angle can be eliminated, the number of components can be reduced.

The vehicle motion control device according to claim 4 is the vehicle motion control device according to claim 3, wherein at least one of the first rotation angle detection unit and the second rotation angle detection unit is decelerated. It is a technical feature that the rotation angle is input via the means. According to the invention set forth in claim 4, since the rotation angle is input to the first and second rotation angle detection means via the deceleration means, the resolution of the input rotation angle can be improved. it can. As a result, the steering angle calculating means described in claim 3 can determine the steering angle of the steering wheel based on the rotation angles 高い pm and vm vm with high resolution. Is also enhanced. Therefore, since the transmission ratio variable mechanism is controlled based on the steering angle of the handle with high resolution, the motion control performance of the vehicle can be improved. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an explanatory diagram showing a schematic configuration of a vehicle motion control device.

FIG. 2 is a functional block diagram showing a vehicle motion control process by EPS_ECU and VGRS_ECU of the vehicle motion control device according to the present embodiment.

FIG. 3 is a flowchart showing a flow of a steering angle calculation process by the VGRS_ECU of the vehicle motion control device according to the present embodiment.

FIG. 4 is an explanatory diagram showing a schematic configuration of a conventional vehicle motion control device.

FIG. 5 is a functional block diagram of a conventional vehicle motion control device. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of a vehicle motion control device to which a vehicle motion control method and a vehicle motion control device of the present invention are applied will be described with reference to the drawings. Note that the mechanical configuration of the vehicle motion control device 20 according to the present embodiment is the same as that of the vehicle motion control device 100 except that the steering angle sensor 26 is omitted. Therefore, in the vehicle motion control device 20 shown in FIG. The same components as those of the vehicle motion control device 100 shown in the drawings are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 2, in the vehicle motion control device 20 according to the present embodiment, two processes, an EPS control process 30a by the EPS-ECU 30 and a VGRS control process 40a by the VGRS_ECU 40, Electronic Control Unit). That is, as described above, the vehicle motion control device 20 has a function of variably controlling the steering gear ratio according to the vehicle speed by the VGRS control process 40a by the VGRS-ECU 40 and the EPS_ECU. The ECU 30 has a function of assisting the driver in steering by generating an assist force according to the steering state by the EPS control processing 30a by 30.

Therefore, in the VGRS control process 40a, the vehicle speed signal V from the vehicle speed sensor 27 and the steering angle Θh obtained by the calculation process as described later are input to the VGRS_ECU 40, so that the vehicle speed signal V is uniquely determined according to the vehicle speed. A process is performed to determine the rotation angle of the gear ratio variable motor 32 m of the variable gear ratio mechanism 32 from the motor rotation angle map (not shown). Supply to variable gear ratio motor 32 m. Thus, in the variable gear ratio mechanism 32 and the VGRS_ECU40, the ratio of the output gear to the input gear is changed in real time by the variable gear ratio motor 32m and the reducer 32g according to the vehicle speed. In the EPS control process 30a, the steering torque signal Tp from the torque sensor 28 and the vehicle speed signal V from the vehicle speed sensor 27 are input to the EPS_ECU 30, so that the EP_ECU 30 is uniquely determined according to the vehicle speed. A process is performed to determine the current command value of the assist motor 24 m of the actuator 24 from the motor current map (not shown), and the motor voltage corresponding to the determined current command value is adjusted by the motor drive circuit by the motor ratio variable motor 3 2 supply to m. Thus, the EPS actuator 24 and the EPS-ECU 30 control the driver's steering according to the driver's steering state and vehicle speed detected by the torque sensor 28 and the vehicle speed sensor 27 by the EPS control processing 30a. The assist motor to assist is generated by the assist motor 24m. As described above, the EPS-control processing by the EPS-ECU 30. The functional outlines of the VGRS-control processing 40a by the VGRS-ECU 40 and the VGRS-control processing 40a by the VGRS-ECU 30 are the same as the vehicle movement control processing by the vehicle movement control apparatus 100 described above. Although basically the same, The vehicle motion control device 20 does not use a steering angle of 0 h detected by a steering angle sensor, but uses VGRS-ECU 40 to calculate and use it in the VGRS control process 40a. The force S differs from the conventional vehicle motion control device 100. That is, as shown in FIGS. 4 and 5, in the vehicle motion control device 100, the steering angle 0h of the steering wheel 21 is mechanically and electrically detected by the steering angle sensor 26, and the steering angle is detected. While 0 h is used in the VGRS control process 40 a, the vehicle operation control device 20 uses the rotation angle θριη and the rotation angle detected by the rotation angle sensor 24 s as shown in FIG. The steering angle Θh of the steering wheel 21 is obtained based on the rotation angle 0vm detected by the sensor 32s, and the VGRS control process 40a is performed based on the obtained steering angle Θh. This makes the steering angle sensor 26 unnecessary.

Specifically, the relationship between the steering angle 0 h of the steering wheel 21, the rotation angle θρηι of the assist motor 24 m, and the rotation angle 0 vm of the variable gear ratio motor 32 m is expressed by the following equation (1). Is satisfied, the VGRS-ECU 40 executes the arithmetic processing by the equation (2) for obtaining the steering angle 0 h of the steering wheel 21 from the equation (1), thereby obtaining the steering angle 0 h.

Θ h + Θ vm / G v = Θ pra / G ρ

θ h = θ pm / G ρ-θ vm / G ν (2)

Here, Gv is a gear ratio (unitless number) by the gear ratio variable mechanism 32, and is set by the VGRS control processing 40a. G p is the gear ratio (unitless number) by the EPS actuator 24 and is set by the EPS control processing 30a.

In the present embodiment, for example, the VGRS-ECU 40 performs the calculation according to the equation (2) by a steering angle calculation process that is periodically (for example, every 5 milliseconds) repeatedly executed by a predetermined timer interrupt process or the like. I have. Here, an outline of the steering angle calculation processing will be described with reference to FIG.

As shown in FIG. 3, in the steering angle calculation process, after a predetermined initialization process, first, in step S101, a process of reading data of the rotation angle θρηι of the assist motor 24m is performed. The data of the rotation angle θριη is detected by the rotation angle sensor 24 s and input to the VGRS-ECU 40, and the data is read by taking it in by an appropriate interrupt processing or the like. Next, in step S103, a process of reading data of the rotation angle θνηι of the gear ratio variable motor 32m is performed. Since the data of the rotation angle θνπι is detected by the rotation angle sensor 32 s and input to the VGRS-ECU 40, the data is read by capturing the data by an appropriate interrupt processing or the like, similarly to the data of the rotation angle Θ pm. Is performed.

In the following step S105, processing of reading data of the gear ratios Gp and Gv is performed. The gear ratio Gp is obtained by multiplying the gear ratio of the ball screw interposed between the output shaft of the variable gear ratio motor 32m and the rack shaft by the gear ratio of the pinion gear that engages the rack of the rack shaft. Is set by design value or measured value. The gear ratio Gv is set by a parameter determined by the VGRS control process 40a.

The gear ratio obtained by multiplying the gear ratio of the ball screw interposed between the output shaft of the assist motor 24m and the rack shaft and the gear ratio of the pinion gear that engages with the rack of the rack shaft is the rotation angle. This corresponds to the reduction ratio of the reduction gear interposed on the input side of the sensor 24 s.

By executing the reading process in steps S101, S103, and S105, all the parameters necessary for obtaining the steering angle 0h from the above-described equation (2) are completed. The processing for calculating the steering angle Θh is performed according to (2). Then, the steering angle 0h obtained in step S107 is passed to the VGRS control processing 40a, and a series of the main steering angle calculation processing ends.

As described above, according to the vehicle motion control device 20 according to the present embodiment, the rotation angle θριη of the assist motor 24 m detected by the rotation angle sensor 24 s and the gear ratio variable motor detected by the rotation angle sensor 32 s The steering angle Θh of the steering wheel 21 is obtained based on the rotation angle θ vm of 32 m, and the VGRS control process 40 a of the gear ratio variable mechanism 32 is performed based on the obtained steering angle Θh. As a result, the steering wheel is determined based on the rotation angle 0 vm used for the VGRS control processing 40 a of the gear ratio variable mechanism 32 and the rotation angle 0 pm used for the EPS control processing 30 a of the EPS actuator 24 (assist motor 24 m). In order to obtain the steering angle Θh of the steering wheel 21, the steering wheel 21 can be used without the steering angle sensor 26 shown in FIG. Steering angle of 0 h can be obtained. Therefore, since such a steering angle sensor 26 can be eliminated, the number of parts can be reduced.

Further, according to the vehicle motion control device 20 according to the present embodiment, the rotation angle 0 pm of the assist motor 24 m is detected in step S 101, and the gear ratio variable motor 32 m is detected in step S 103. The rotation angle 0 vm is detected, and the steering angle Θh of the steering wheel 21 is obtained based on the rotation angle θ ριη and the rotation angle θ νιη in step S 107. Then, the VGRS control process 40a of the variable gear ratio mechanism 32 is performed based on the steering angle 0h obtained in step 107. This allows the variable gear ratio mechanism

3 Rotation angle 0 vm used for V GRS control processing 40 a and rotation angle used for EPS control processing 30 a for EPS actuator 24 (assist motor 24 m)

Since the steering angle Θh of the steering wheel 21 is obtained based on 0 pm, the steering angle Θh of the steering wheel 21 can be obtained without the steering angle sensor 26 shown in FIG. Therefore, since such a steering angle sensor 26 can be eliminated, the number of parts can be reduced.

Further, in the vehicle motion control device 20 according to the present embodiment, as in the conventional vehicle motion control device 100 shown in FIG.

Not used for 40a. Therefore, the response of the control loop of the variable gear ratio mechanism 32 is reduced due to the decrease in the resolution of the current command value, which occurs when the resolution of the detected angle is used as the steering angle sensor 26, and the steering due to the response delay is reduced. Occurrence of vibration and the like of the wheel 21 can be suppressed.

The gear ratio obtained by multiplying the gear ratio by the ball screw interposed between the output shaft of the assist motor 24 m and the rack shaft and the gear ratio by the pinion gear that engages the rack of the rack shaft is Since the rotation angle sensor 24 s functions as a reduction gear interposed on the input side of the rotation angle sensor 24 s, the rotation angle sensor 24 s that detects the rotation angle 0 pm of the assist motor 24 m is connected to the rotation angle sensor 24 s via the reduction gear. The rotation angle θ ρηι is input. As a result, the resolution of the input rotation angle θ ρηι can be increased, and in step S 107, the steering angle 0 h of the steering wheel 21 can be obtained based on the high-resolution rotation angle θ ρηι. However, the performance of the obtained steering angle られる h can be enhanced. Therefore, the VGRS control process 40a of the variable gear ratio mechanism 32 is performed based on the steering wheel angle Θh of the high-resolution steering wheel 21, thereby improving the vehicle motion control performance. Can be

In addition, since the reducer 32 g of the variable gear ratio mechanism 32 functions as a reducer interposed on the input side of the rotation angle sensor 32 s, the rotation angle Θ vm of the variable gear ratio motor 32 m is detected. The rotation angle Θvm is input to the rotation angle sensor 32 s via the speed reducer. As a result, the resolution of the input rotation angle of 6 vm can be increased, and in step S107, the steering angle Θh of the steering wheel 21 can be obtained based on the rotation angle θ νηι with high resolution. The resolution of the calculated steering angle Θh can be increased. Therefore, the VGRS control process 40a of the variable gear ratio mechanism 32 is performed based on the steering angle 0h of the high-resolution steering wheel 21, so that the motion control performance of the vehicle can be improved.

Claims

The scope of the claims

1. A variable transmission ratio mechanism that varies the transmission ratio by driving a variable gear ratio motor in the middle of the steering transmission system that connects the steering wheel and the steered wheels, and a steering torque generated on the output shaft of the variable transmission ratio mechanism. And an assist motor that captures the steering force by using

A first step of detecting a rotation angle 0 pm of the assist motor;

A second step of detecting a rotation angle θ νιη of the variable gear ratio motor, and the rotation angle 0 pm detected in the first step and the rotation angle θ νιη detected in the second step. A third step for determining the steering angle of the steering wheel; and

A motion control method for a vehicle, comprising controlling the transmission ratio variable mechanism based on the steering angle of the steering wheel obtained in the third step.

2. The detection of the rotation angle θ ριη in the first step and / or the detection of the rotation angle θ νηι in the second step are characterized in that the rotation angle is input via a deceleration means. The vehicle motion control method according to claim 1, wherein:

3. A variable transmission ratio mechanism that varies the transmission ratio by driving a variable gear ratio motor in the middle of the steering transmission system that connects the steering wheel and the steered wheels, and a steering torque generated on the output shaft of the variable transmission ratio mechanism. And an assist motor that supplements the steering force by using

First rotation angle detection means for detecting a rotation angle of 0 pm of the assist motor, second rotation angle detection means for detecting a rotation angle Θ vm of the variable gear ratio motor, and the first rotation angle detection means Steering angle calculation means for determining the steering angle of the steering wheel based on the rotation angle pm pm detected by and the rotation angle 6 vm detected by the second rotation angle detection means,

A motion control device for a vehicle, comprising: controlling the transmission ratio variable mechanism based on a steering angle of the steering wheel obtained by the steering angle calculation means.

4. The vehicle according to claim 3, wherein a rotation angle is input to at least one of the first rotation angle detection unit and the second rotation angle detection unit via a speed reduction unit. Motion control device.